Project description:Clostridium difficile is an important nosocomial pathogen associated particularly with diarrheal disease in elderly individuals in hospitals and long-term care facilities. We examined the carriage rate of Clostridium difficile by culture as a function of fecal microbiota composition in elderly subjects recruited from the community, including outpatient, short-term respite, and long-term hospital stay subjects. The carriage rate ranged from 1.6% (n = 123) for subjects in the community, to 9.5% (n = 43) in outpatient settings, and increasing to 21% (n = 151) for patients in short- or long-term care in hospital. The dominant 072 ribotype was carried by 43% (12/28) of subjects, while the hypervirulent strain R027 (B1/NAP1/027) was isolated from 3 subjects (11%), 2 of whom displayed C. difficile associated diarrhea (CDAD) symptoms at the time of sampling. Emerging ribotypes with enhanced virulence (078 and 018) were also isolated from two asymptomatic subjects. Pyrosequencing of rRNA gene amplicons was used to determine the composition of the fecal microbiota as a surrogate for the microbial population structure of the distal intestine. Asymptomatic subjects (n = 20) from whom C. difficile was isolated showed no dramatic difference at the phylum or family taxonomic level compared to those that were culture negative (n = 252). However, in contrast, a marked reduction in microbial diversity at genus level was observed in patients who had been diagnosed with CDAD at the time of sampling and from whom C. difficile R027 was isolated.
Project description:Despite a large increase in Clostridium difficile infection (CDI) severity, morbidity and mortality in the US since the early 2000s, CDI burden estimates have had limited generalizability and comparability due to widely varying clinical settings, populations, or study designs.A decision-analytic model incorporating key input parameters important in CDI epidemiology was developed to estimate the annual number of initial and recurrent CDI cases, attributable and all-cause deaths, economic burden in the general population, and specific number of high-risk patients in different healthcare settings and the community in the US. Economic burden was calculated adopting a societal perspective using a bottom-up approach that identified healthcare resources consumed in the management of CDI.Annually, a total of 606,058 (439,237 initial and 166,821 recurrent) episodes of CDI were predicted in 2014: 34.3 % arose from community exposure. Over 44,500 CDI-attributable deaths in 2014 were estimated to occur. High-risk susceptible individuals representing 5 % of the total hospital population accounted for 23 % of hospitalized CDI patients. The economic cost of CDI was $5.4 billion ($4.7 billion (86.7 %) in healthcare settings; $725 million (13.3 %) in the community), mostly due to hospitalization.A modeling framework provides more comprehensive and detailed national-level estimates of CDI cases, recurrences, deaths and cost in different patient groups than currently available from separate individual studies. As new treatments for CDI are developed, this model can provide reliable estimates to better focus healthcare resources to those specific age-groups, risk-groups, and care settings in the US where they are most needed. (Trial Identifier ClinicaTrials.gov: NCT01241552).
Project description:BackgroundThere is a paucity of contemporary national estimates for Clostridium difficile infection (CDI) hospitalizations by age group, sex, and region in the US population. Also, there is lack of contemporary national statistics on CDI hospitalizations with comorbidities.MethodsWe analyzed the 2017 National Inpatient Sample (NIS) to determine the population-based rates of CDI hospitalizations, characteristics of hospitalizations with CDI, and the rates of comorbidities associated with CDI hospitalizations.ResultsThere were 329,460 CDI-related hospitalizations in 2017 (almost 1% of all hospitalizations). The average age for patients admitted with CDI as a principal or secondary diagnosis was 64.7 years (almost 20 years older when compared with all other hospitalizations). Patients 85 years and older had the highest rate of CDI hospitalizations (716 per 100,000 hospitalizations), and patients less than 18 years of age had the lowest rate (12 per 100,000 hospitalizations). There was a progressive increase in the CDI hospitalization rates with each successive age group. The hospitalization rates were higher in females (114 per 100,000 hospitalizations) than males (88 per 100,000 hospitalizations). The CDI hospitalization rate was highest in the Northeast (109 per 100,000 hospitalizations) and lowest in the West (84 per 100,000 hospitalizations). Fluid and electrolyte disturbance (63.3%) and renal failure (33.4%) were the two most common comorbidities associated with CDI hospitalizations. When CDI is a secondary diagnosis, major loss of function, extreme likelihood of dying, septicemia, and septic shock were more common in comparison to CDI as a principal diagnosis.ConclusionsCDI hospitalization rates were highest in the elderly over 85 years old and declined with successive decreases in age. Women had higher CDI hospitalization rates than men, and fluid and electrolyte disturbances and renal failure were the most common comorbid conditions. The presence of CDI as a comorbid condition at the time of hospitalization for other principal diagnoses or development of CDI during a hospitalization for other principal diagnoses significantly increases the risk of in-hospital morbidity and mortality.
Project description:Community-associated Clostridium difficile infection (CDI) appears to be an increasing problem. Reported carriage rates by C. difficile are debatable with suggestions that primary asymptomatic carriage is associated with decreased risk of subsequent diarrhoea. However, knowledge of potential reservoirs and intestinal carriage rates in the community, particularly in the elderly, the most susceptible group, is limited. We have determined the presence of C. difficile in the faeces of a healthy elderly cohort living outside of long-term care facilities (LCFs) in the United Kingdom.Faecal samples from 149 community-based healthy elderly volunteers (median age 81 years) were screened for C. difficile using direct (Brazier's CCEY) and enrichment (Cooked Meat broth) culture methods and a glutamate dehydrogenase (GDH) immunoassay. Isolates were PCR-ribotyped and analysed for toxin production and the presence of toxin genes.Of 149 faecal samples submitted, six (4%) were found to contain C. difficile. One particular sample was positive by both the GDH immunoassay and direct culture, and concurrently produced two distinct strain types: one toxigenic and the other non-toxigenic. The other five samples were only positive by enrichment culture method. Overall, four C. difficile isolates were non-toxigenic (PCR-ribotypes 009, 026 (n?=?2) and 039), while three were toxigenic (PCR-ribotypes 003, 005 and 106). All individuals who had a positive culture were symptom-free and none of them had a history of CDI and/or antibiotics use in the 3 month period preceding recruitment.To our knowledge, this is the first study of the presence of C. difficile in healthy elderly community-dwelling individuals residing outside of LCFs. The observed carriage rate is lower than that reported for individuals in LCFs and interestingly no individual carried the common epidemic strain PCR-ribotype 027 (NAP1/BI). Further follow-up of asymptomatic carriers in the community, is required to evaluate host susceptibility to CDI and identify dynamic changes in the host and microbial environment that are associated with pathogenicity.
Project description:Data are limited on the attributable outcomes of Clostridium difficile-associated disease (CDAD), particularly in CDAD-endemic settings. We conducted a retrospective cohort study of nonsurgical inpatients admitted for >/=48 hours in 2003 (N = 18,050). The adjusted hazard ratios for readmission (hazard ratio 2.19, 95% confidence interval [CI] 1.87-2.55) and deaths within 180 days (hazard ratio 1.23, 95% CI 1.03-1.46) were significantly different among CDAD case-patients and noncase patients. In a propensity score matched-pairs analysis that used a nested subset of the cohort (N = 706), attributable length of stay attributable to CDAD was 2.8 days, attributable readmission at 180 days was 19.3%, and attributable death at 180 days was 5.7%. CDAD patients were significantly more likely than controls to be discharged to a long-term-care facility or outside hospital. Even in a nonoutbreak setting, CDAD had a statistically significant negative impact on patient illness and death, and the impact of CDAD persisted beyond hospital discharge.
Project description:Background:The economic burden of Clostridium difficile infection (CDI), the leading cause of nosocomial infectious diarrhea, is not well understood. The objective of this study was to estimate the healthcare resource utilization (HCRU) and costs attributable to primary CDI and recurrent CDI (rCDI). Methods:This is a database (MarketScan) study. Patients without CDI were matched 1:1 by propensity score to those with primary CDI but no recurrences to obtain HCRU and costs attributable to primary CDI. Patients with primary CDI but no recurrences were matched 1:1 by propensity score to those with primary CDI plus 1 recurrence in order to obtain HCRU and costs attributable to rCDI. Adjusted estimates for incremental cumulative hospitalized days and healthcare costs over a 6-month follow-up period were obtained by generalized linear models with a Poisson or gamma distribution and a log link. Bootstrapping was used to obtain 95% confidence intervals (CIs). Results:A total of 55504 eligible CDI patients were identified. Approximately 25% of these CDI patients had rCDI. The cumulative hospitalized days attributable to primary CDI and rCDI over the 6-month follow-up period were 5.20 days (95% CI, 5.01-5.39) and 1.95 days (95% CI, 1.48-2.43), respectively. The healthcare costs attributable to primary CDI and rCDI over the 6-month follow-up period were $24205 (95% CI, $23436-$25013) and $10580 (95% CI, $8849-$12446), respectively. Conclusions:The HCRU and costs attributable to primary CDI and rCDI are quite substantial. It is necessary to reduce the burden of CDI, especially rCDI.
Project description:Clostridium difficile is being recognized as a growing threat to many health-care systems. Epidemiology data shows that infection rates are soaring and the disease burden is increasing. Despite the efficacy of standard treatments, it is becoming evident that novel therapeutics will be required to tackle this disease. These new treatments aim to enhance the intestinal microbial barrier, activate the immune system and neutralize the toxins that mediate this disease. Many of these therapies are still in the beginning stages of investigation, however, in the next few years, more clinical data will become available to help implement many of these exciting new therapeutic approaches.
Project description:Clostridium difficile (Cd) is a gram-positive, spore-forming bacterium and the primary cause of nosocomial diarrhea and pseudomembranous colitis. The pathogenicity of Cd has been linked to its production of TcdA and TcdB. While they cause fluid secretion, inflammation, and colonic damage, their respective and synergistic roles have been difficult to ascertain. In infection animal model, TcdB has been demonstrated to be a key virulence factor, and TcdB causes obvious damage in human and porcine colonic explants. Using the colonic epithelia derived from cloned colonic stem cells, we have developed a model to test the response to TcdB. Epithelia generated in air-liquid interface cultures from cloned transverse colon stem cells were challenged with TcdB at different concentrations and durations.
Project description:Clostridium difficile is a common cause of infectious diarrhea in hospitalized patients. A severe and increased incidence of C. difficile infection (CDI) is associated predominantly with the NAP1 strain; however, the existence of other severe-disease-associated (SDA) strains and the extensive genetic diversity across C. difficile complicate reliable detection and diagnosis. Comparative genome analysis of 14 sequenced genomes, including those of a subset of NAP1 isolates, allowed the assessment of genetic diversity within and between strain types to identify DNA markers that are associated with severe disease. Comparative genome analysis of 14 isolates, including five publicly available strains, revealed that C. difficile has a core genome of 3.4 Mb, comprising ? 3,000 genes. Analysis of the core genome identified candidate DNA markers that were subsequently evaluated using a multistrain panel of 177 isolates, representing more than 50 pulsovars and 8 toxinotypes. A subset of 117 isolates from the panel had associated patient data that allowed assessment of an association between the DNA markers and severe CDI. We identified 20 candidate DNA markers for species-wide detection and 10,683 single nucleotide polymorphisms (SNPs) associated with the predominant SDA strain (NAP1). A species-wide detection candidate marker, the sspA gene, was found to be the same across 177 sequenced isolates and lacked significant similarity to those of other species. Candidate SNPs in genes CD1269 and CD1265 were found to associate more closely with disease severity than currently used diagnostic markers, as they were also present in the toxin A-negative and B-positive (A-B+) strain types. The genetic markers identified illustrate the potential of comparative genomics for the discovery of diagnostic DNA-based targets that are species specific or associated with multiple SDA strains.
Project description:Clostridium difficile is a major identifiable and treatable cause of antibiotic-associated diarrhea. Poor nutritional status contributes to mortality through weakened host defenses against various pathogens. The primary goal of this study was to assess the contribution of a reduced protein diet to the outcomes of C. difficile infection in a murine model.C57BL/6 mice were fed a traditional house chow or a defined diet with either 20% protein or 2% protein and infected with C. difficile strain VPI10463. Animals were monitored for disease severity, clostridial shedding and fecal toxin levels. Select intestinal microbiota were measured in stool and C. difficile growth and toxin production were quantified ex vivo in intestinal contents from untreated or antibiotic-treated mice fed with the different diets.C. difficile infected mice fed with defined diets, particularly (and unexpectedly) with protein deficient diet, had increased survival, decreased weight loss, and decreased overall disease severity. C. difficile shedding and toxin in the stool of the traditional diet group was increased compared with either defined diet 1 day post infection. Mice fed with traditional diet had an increased intestinal Firmicutes to Bacteroidetes ratio following antibiotic exposure compared with either a 2% or 20% protein defined nutrient diet. Ex vivo inoculation of cecal contents from antibiotic-treated mice showed decreased toxin production and C. difficile growth in both defined diets compared with a traditional diet.Low protein diets, and defined nutrient diets in general, were found to be protective against CDI in mice. Associated diet-induced alterations in intestinal microbiota may influence colonization resistance and clostridial toxin production in a defined nutrient diet compared to a traditional diet, leading to increased survival. However, mechanisms which led to survival differences between 2% and 20% protein defined nutrient diets need to be further elucidated.